1. Field of the Invention
The present invention relates to a play data detecting system for an electronic musical instrument which is provided with means for multiplexing together and scanning note select signals from key switches and function select signals from tablet switches and analog volumes.
2. Description of the Prior Art
Heretofore there has been proposed, for instance, in U.S. Pat. No. 4,046,047 (patented Sept. 6, 1977) a system for multiplexing and scanning note select signals from key switches and function select signals from tablet switches and analog volumes on the same line. With the abovesaid prior art system, however, the key switch signal and the tablet switch signal are each assigned only once in one scanning period and the tablet switch signal is sampled more than necessary.
Recently there has been widely used a play data detector of the type employing a microcomputer but, in the case of using such a sequential control element, the length of the processing time is a very important problem. That is to say, in the case where the key switch signal and the tablet switch signal are each assigned only one time slot in one scanning period as in the prior art, it may sometimes be difficult to follow the speed of play data in a block which requires high-speed sampling, such as block of key switches. This arises from equally handling the key switch signal which must be sampled at high speed and the tablet switch signal which may be sampled at relatively low speed.